Atm-based distributed network switching system

A distributed switching system for setting up and connecting a telephone call, originating with originating telephone network and terminating on a telephone network termination, for transmission through a network of distributed ATM switching, the system comprising: an element ( 18), which resides outside the distributed ATM switching network, to receive a signaling message to a phone call from the originating telephone network with common channel signaling narrow band; a device (30) interworking function and control (CS-IWF) centralized signaling to provide processing and control of the telephone call within the network distributed ATM switching, the device (30) (CS-IWF) being connected to receive the common channel signaling narrowband from the element (18) network and having an interface for providing processing and establishment of the telephone call within the network distributed ATM switching with broadband signaling according to the signaling message.